The partial or total blockage of small arteries, such as the coronary arteries providing blood to the heart, may result in ischemia and permanent tissue damage. Many therapies are used to improve coronary blood flow. For example, intraaortic balloon pumps (IABP) are used, in part, to augment coronary circulation by the principle of counter-pulsation. These are commonly used for up to 72 hours.
Where more permanent solution is required to the blockage of the specific arteries, surgery can be performed to put in place a "bypass" to move blood around the occluded artery portion. One very commonly used procedure of this type is the coronary artery bypass.
Other methods are used for opening the occlusion, such as balloon angioplasty which uses an inflatable member to expand a blocked area. Another family of devices breaks up and removes the stenosis blocking the artery. This is commonly known as atherectomy. This is performed by mechanical means as well as lasers.
In cases where the coronary artery disease is more wide spread, it is difficult to treat the disease with these prior art methods. The more diffuse the disease, the more difficult it is to use the existing therapies.
It is well known in the art to use trained skeletal muscle as an implantable pump. For example, see U. S. Pat. No. 4,411,268 to Cox which discloses muscle training methods. Such muscle pumps are well known in the area of cardiac assist for improving blood flow in the aorta as taught by Ray C.J. Chiu, M.D. in his book "Biomechanical Cardiac Assist".
The concept of providing flow from the aorta to coronary arteries by a bypass is known. A side-by-side anastomosis of this type shunt to the various arteries is demonstrated in the prior art. These attempts have not, however, recognized the need for a pump to assist in providing blood to these coronary arteries.
What is needed is a therapy that can provide blood flow through the coronary arteries generally so as to treat diffuse coronary artery problems and which has a capability, when desired, to provide assisted blood flow to the heart, especially during diastole, when the heart muscle around the diseased arteries is relaxed.